<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <script>
        var flag = false;
        if (flag){
            console.log("条件为true");
        }
        else{
            console.log("条件为false");
        }

        var day = 3
        if (day === 1){
            console.log("今天是星期一");
        }
        else if (day === 2){
            console.log("今天是星期二");
        }
        else if (day === 3){
            console.log("今天是星期三");
        }
        else if (day === 4){
            console.log("今天是星期四");
        }
        else if (day === 5){
            console.log("今天是星期五");
        }
        else if (day === 6){
            console.log("今天是星期六");
        }
        else if (day === 7){
            console.log("今天是星期天");
        }
        else{
            console.log("输入错误");
        }
    </script>
</body>
</html>